8 Common Problems Your Solar Hot Water & What To Do

It’s easy to see why so many Brisbane homes are switching to solar. A good solar hot water system can slash your energy bills, reduce your carbon footprint, and give you steady hot water powered by the sun – which, here in Queensland, we have no shortage of. These systems are highly efficient and, when maintained properly, extremely reliable. But is your solar hot water not working?

First, don’t panic – because even the best systems can run into trouble over time. If your troublesome solar hot water system has left you with cold showers, strange noises, or a really stressful puddle on the roof, it’s not the end of the world. Most issues are actually pretty simple to diagnose and fix quickly with the right help.

Let’s run through the most common problems with solar hot water systems – and what to do next.

1. Solar hot water not heating up?

Solar hot water not heating properly? It usually comes down to one of three things:

• The booster isn’t turning on (or has been left off)
• A thermostat or element has failed
• There’s not enough sunlight hitting the panels.

Try this first: on cloudy weeks, make sure your electric or gas booster is switched on. If you have an electric model, the solar hot water booster switch not working is a common culprit. Sometimes it’s a faulty switch, a tripped circuit breaker, or a failed booster element. A quick test from a licensed plumber can confirm the cause – and it’s often a fast fix.

2. Solar hot water system leaking?

A solar hot water leaking tank or pipe can look alarming, and sometimes it really is – but it’s not always a disaster. Many systems naturally discharge a small amount of water through the temperature and pressure relief (TPR) valve, especially on hot days. That’s normal.

If you see continuous dripping, however, you might have a solar hot water system leaking from a fitting or valve that’s worn out. Replacing that part usually costs far less than replacing the entire system.

Leaks coming from the top of your home – a solar hot water system leaking on the roof, for instance – can indicate a perished seal or loose connection between the tank and collector panels. Again, a plumber can tighten or replace seals before damage spreads.

3. Hot water solar panel leaking?

When your hot water solar panel leaking is visible on the roof, that means the copper pipes within the collectors have likely developed a small split, often from corrosion or expansion stress. You might notice reduced heating performance or small water stains on the roof below.

This sounds serious – but it’s often repairable. The collector panels can usually be serviced or replaced individually without changing the whole system. If they’re older, though, an upgrade might be more efficient in the long run – newer panels perform better and resist corrosion.

4. Solar hot water booster not working?

Your booster is what keeps hot water running when the sun can’t. If your solar hot water booster is leaving you with cold water during overcast weeks, it’s often one of these:

• A tripped circuit or faulty power supply
• A blown heating element
• A broken thermostat
• For gas models, ignition or gas flow issues.

Booster parts are straightforward to replace and far cheaper than a new unit. Modern systems also have indicator lights that help identify the problem, so your hot water plumber can fix it quickly on-site.

5. System leaking internally or from valves?

A leaking solar hot water system can lose efficiency very quickly if not repaired. The most common causes are:

• A corroded tank (especially in older steel cylinders)
• Faulty pressure valves
• Cracked fittings from expansion and contraction.

If you’re wondering how to fix leaking solar hot water system issues like these, the answer depends on where the leak is:

• Small valve leaks can often be replaced affordably
• But if the tank itself is rusting through, replacement is usually the safest move.

And remember – brand new systems are usually far more energy-efficient.

6. Aging or inefficient systems?

Every solar setup eventually reaches the end of its service life. So, how long does a solar hot water system last?

The answer is typically between 10 and 15 years for most modern systems – although some will last a lot longer with regular professional hot water servicing.

If you’ve had your system for over a decade and it’s showing signs of reduced performance, it may be time to upgrade. Not only are new models lighter, safer, and more efficient, but rebates and technology improvements also make replacement surprisingly affordable.

So how long do solar hot water systems last is a question that really depends on how they’re maintained. Annual checks can easily add several more years to their lifespan, with your hot water plumber checking closest for:

• Leaks
• Malfunctioning pressure valves
• And panel condition.

7. Temperature fluctuations or weak pressure?

If your water alternates between hot and cold, or pressure drops suddenly, airlocks or scaling inside pipes can be the cause.

Hard water buildup can restrict flow through collectors or heat exchangers. These problems develop slowly, so regular servicing prevents major performance loss.

8. Poor installation or lack of servicing?

Sometimes the problem isn’t the product – it’s how it was installed.

Incorrect work on all of these can cause long-term issues:

• Incorrect pipe gradients
• Poor insulation
• Unbalanced valves.

Regular servicing every one to two years ensures every component is checked, the system is flushed, and the unit recalibrated, keeping your system at peak performance.

When it’s time to call a professional

Solar hot water systems are high-pressure, high-temperature setups connected to your home’s electrical or gas supply – not something to DIY. Is your solar panel leaking? Has your booster failed? Call a licensed hot water plumber. They can test, repair, or replace components safely and quickly.

At S&J Hot Water Brisbane, we diagnose and fix every type of solar issue – leaks, boosters, controllers, full hot water repairs and replacements – the works. And we do it all with fixed pricing and same-day service. We work with all the top brands like Rinnai, Rheem, Bosch, and Dux – so your system gets the right parts and care.

Get your hot water back fast

Solar hot water system not working? Don’t let a small solar issue leave you with cold showers. Whether it’s a solar hot water system leaking from the bottom or simply not heating properly, our friendly Brisbane team can repair, replace, or service your system the same day.

Call or book online now for reliable solar hot water repairs anywhere across Brisbane.